The present invention relates to polymers and copolymers of macrocyclic metal chelators, such as porphyrins and phthalocyanines, to methods for the preparation thereof and to the use of metal complexes thereof as catalysts for reactions in solution or vapor phase.
The broad class of compounds known as macrocyclic metal chelators embraces many compounds which have substantial utility for a wide variety of chemical applications. For example, tetraphenyl porphyrins which are betasubstituted by halogen and/or bear electronegative substituents on the phenyl are known as catalysts in a variety of oxidative reactions. For example, iron(III) substituted porphyrins have been studied as catalysts for epoxidations using pentafluoroiodosylbenzene. (Traylor, T. G. et al., J. Am. Chem. Soc. 107:5537 (1985)]. The use of an iron tetrakis (2,6-dichlorophenyl)octabromoporphyrin complex as a stable catalyst of high turnover catalytic hydroxylations has also been reported [Traylor T. G. and Tsuchiya, T., Inorg. Chem. 26:1338 (1987)].
U.S. Pat. No. 4,892,941 to Dolphin et al., the entire disclosure of which is hereby incorporated by reference, discloses a class of transition metal porphyrin complexes which are useful in the oxidation of lignin and lignin-model compounds, the conversion of alkanes to alcohols and the conversion of alkenes to epoxides. Of particular interest to Dolphin et al. are the water soluble compounds (i.e., compounds which are substituted with water-solubilizing electronegative groups).
U.S. Pat. No. 4,917,784 to Shelnutt, the entire disclosure of which is also incorporated by reference, describes a process for the oxidation of hydrocarbons using molecular oxygen in a catalytic cycle driven by an artificial photosynthesis system which mimics the cytochrome P.sub.450 reaction to oxidize alkanes and olefins. The system includes a tin(IV) or antimony(V) porphyrin photosynthesizer and an iron or manganese porphyrin hydrocarbon-oxidation catalyst. The preferred hydrocarbon-oxidation catalyst is Fe tetrakis(pentafluorophenyl)porphyrin chloride.
U.S. Pat. Nos. 4,774,356 and 4,904,745 to Inoue et al., the entire disclosures of which are also incorporated by reference, describe the polymerization of alkylene oxides in the presence of a reaction product of an aluminum porphyrin complex and an active hydrogen-containing compound. The aluminum porphyrin complex is suitably prepared by reacting an organoaluminum compound with a porphyrin compound. Similarly, U.S. Pat. Nos. 4,565,845 and 4,665,134 to Inoue et al. (also incorporated by reference herein) describe the use of aluminum porphyrin complexes as catalysts for producing block copolymers having a narrow molecular weight distribution.
A major disadvantage of the soluble porphyrins hereinbefore described is the necessity to separate the porphyrins from the reaction mixture. Accordingly, it would be useful to provide the catalytic activity of the known porphyrin complexes in a solid form.
U.S. Pat. No. 4,315,998 to Neckers et al. describes a method of preparing a polymer-bound photosensitizing catalyst for use in heterogeneous catalysis of photosensitized chemical reactions, which comprises forming a mixture of a polymeric material having attached thereto an available leaving group capable of being displaced in a nucleophilic displacement reaction and a photosensitizing catalytic compound containing in its molecule a nucleophile which is capable of displacing the leaving group on the polymer. Among the photosensitizers mentioned in the patent is hemin.
U.S. Pat. No. 4,724,062 to Naarmann et al. describes a process for applying a layer of an electrically conductive polymer to carbon fibers, filaments or sheet-like structures. A solution of a sulfonic acid of a phthalocyanine or porphyrin is applied to the carbon structures and dried, so that the carbon structures are coated with a layer of the sulfonic acid. The coated material is then used as the anode in a solution which contains a 5-membered heterocycle, and the monomers are anodically polymerized. The resultant products are described as exhibiting thermal stability and good electrical conductivity.
U.S. Pat. No. 4,800,188 to Shepherd describes a method for supporting metalloporphyrins on microporous polybenzimidazole articles. The polybenzimidazoles are treated with a strong base to produce an anionized material, which is then mixed with a solution of a metalloporphyrin salt to produce a microporous polybenzimidazole metalloporphyrin complex. The products are described as useful in the selective oxidation of alkanes, olefins and aromatic compounds, as well as in the separation of oxygen from a gas stream.
U.S. Pat. No. 4,806,514 to Langford et al. describes a composite photocatalyst for treatment of refractory waste, comprising particles of a wide band gap semiconductor material coated with a polymer film capable of absorbing a refractory waste. The film comprises a pyridine-containing polymer and a divalent metal porphyrin or metal phthalocyanine dye which is molecularly dispersed throughout the film and chemically bonded to the pyridine-containing polymer. In a preferred embodiment, the film comprises polyvinylpyridine or a copolymer of vinylpyridine with styrene blended with a cationic ionomer to form a cationic film which incorporates the porphyrin or phthalocyanine at cationic sites, with the polyvinylpyridine or copolymer being available for coordination.
U.S. Pat. No. 4,861,454 and 4,957,615 to Ushizawa et al. describe oxygen sensors comprising an electrically conductive substrate directly coated with an electrolytic oxidative polymeric membrane containing an aryl-substituted porphyrin compound or a metal complex thereof. The aryl-substituted porphyrin bears on the aryl groups thereof a substituent group (preferably, in the ortho- and/or parapositions) which participates at the time of electrolytic oxidative polymerization.
U.S. Pat. No. 4,908,442 to Narang et al. describes tetraketoneporphyrin monomers and methods for the preparation thereof, as well as polymers prepared by reacting the tetraketone monomers with a tetraamine-substituted aromatic moiety having at least one aromatic ring. The polymers are described to be useful as liquid crystals and in non-linear optical devices.
U.S. Pat. No. 4,917,800 to Lonsdale et al. describes thin film composite membranes comprising a microporous polymeric membrane support and an ultrathin membrane which comprises the interfacial polymerization reaction product of monomers that are mutually reactive in a condensation reaction, at least one of the monomers being a porphyrin or phthalocyanine. The resultant asymmetric membranes are described as particularly well-suited for use in artificial photosynthesis.
U.S. Pat. No. 5,011,907 to Beratan describes highly conjugated organic polymers with "defects" introduced into the polymer chain to enhance the hyperpolarizability of the molecules. The polymers comprise a chain of alternating single and double bonds or a chain of alternating single and triple bonds, and are characterized by the presence of a moiety in the chain which donates or accepts electrons. In Table 2, there is described a hypothetical molecule comprising repeating units consisting of a porphyrin/quinone donor/acceptor pair flanked by vinyl moieties. No teaching or suggestion is provided as to how such a hypothetical molecule might be prepared.
U.S. Pat. No. 5,011,956 to Ford et al. describes polymer latexes comprising colloidal suspensions of charged polymer particles containing charged metal complexes prepared from charged polymer colloids by ion exchange. The metal may be complexed by a porphyrin or phthalocyanine.
Recently, Kojima et al. described a dehydration reaction of poly(methacrylic acid) (PMAA) with hemin to prepare a hemin-PMAA anhydride. The PMAA was reported as bearing up to 1.8 mol% of porphyrin rings. The results of oxygen absorption experiments suggested that the hemin-PMAA product could act as an oxygen absorber [Kojima, T. et al., J. Polym. Sci. Part C: Polymer Letters 28:129 (1990)].
Kadish et al. describe a reaction product of 5,10,15,20-tetrakis(pentafluorophenyl)porphine [(TF.sub.5 PP)H.sub.2 ] and cobalt acetate in dimethylformamide, in which they speculate that fluorine in a para-position on one or more of the phenyl substituents had been replaced by a --N(CH.sub.3).sub.2 group [Kadish et al., J. Am. Chem. Soc. 112:8364-8368 (1990)]. The authors speculate that the amine was generated in the course of decomposition of dimethyiformamide used as a solvent and may have replaced a fluorine atom on one or more phenyl rings of the TF.sub.5 pp complex via aromatic nucleophilic substitution.
Kellman and coworkers have described phase transfer catalyzed substitutions and polymerizations of hexafluorobenzene and 4,4'-dichlorodiphenylsulfone with various phenols, bisphenols and bisthiophenols via nucleophilic replacement reactions using 18-crown-6 ether as a catalyst [Keliman et al., Polymer Preprints 21:164-165 (1980); Keliman et al., Polymer Preprints 22:383-384 (1981); Gerbi et al., Polymer Preprints 22:385-386 (1981); Gerbi et al., Polymer Preprints 22:387-388 (1981)]. It is reported that in the absence of 18-crown-6 ether, polymerization does not occur.
It is an object of the present invention to provide novel compositions of matter which exhibit the same utilities as the heretofore-known macrocyclic metal chelators, but which are generally insoluble in the most commonly-used solvents, and methods for the preparation and use thereof.
It is a particular object of the present invention to provide novel catalysts based upon particular types of known macrocyclic metal chelators, such as porphyrins and phthalocyanines, which are useful in the catalysis of reactions in the liquid and vapor phases, as well as methods for the preparation and use thereof.